One-off Shelby Super Snake for sale

Super rare Ford Mustang GT500 built for tyre test now coming up for auction…

Praise be to Carroll Shelby. This is a man who raced in Formula One in '58 and '59, set 16 American and international speed records in an Austin Healey 100S, won the Le Mans 24 Hours in an Aston Martin DBR1, and spent the remainder of his life building treacherously quick cars.

Much like the insanely cool white one above. It's a 1967 Ford Mustang, purpose built for Goodyear to test a (then) new type of tyre called the ‘Thunderbolt'. But this is no ordinary ‘Stang: it's a one-off GT500 ‘Super Snake'. The original Super Snake.

It all started with the '67 Mustang. Ford released it with a V8, and Shelby did the honourable thing by deciding an even bigger V8 was required; he dropped in a modified Police Interceptor 428 CI engine - producing some 355bhp - and thus, the original GT500 was born. It outsold its standard Ford GT350 stablemate by 2,048 units to 1,175, catching the eye of Goodyear. They asked Shelby if he'd take part in a promotional gig - a high speed demonstration run of its skinny whitewall ‘Thunderbolt' tyre.

Shelby said yes, and selected the GT500 as the car. But one of Shelby's friends, a chap called Don McCain, suggested Shelby build that GT500 into a ‘super' GT500. Shelby, predictably, said yes. And so he instructed his chief engineer to prepare a GT500 with a lightweight, 427 racing engine - the same engine that powered the Ford GT40 Mk II to Le Mans victory (beating Ferrari of course).

It featured aluminium heads, an aluminium water pump, a forged crank, Le Mans-spec con rods, and the ‘bundle of snakes' exhaust system seen on the GT40. In total, it produced around 600bhp and could run at a sustained 6,000rpm. Shelby's engineer also fitted an external oil cooler, braided lines, a remote oil filter and stiffer springs and shocks mounted on the passenger side (to counteract high speed cornering forces).

Then, to complete the look, it was fitted with a one-off chrome headlight surround and Le Mans-blue stripes across the body. Shelby then decked the ten-spoke aluminium 15in wheels with Goodyear's Thunderbolt tyres - inflated with nitrogen to keep the sidewalls rigid - and embarked on some demonstration laps around Texas. Shelby himself took the car up to 170mph, and his engineer Fred Goodell then spent 500 miles at a constant 142mph. The tyres? They came back with 97 per cent of their original tread.

But the plans for the Super Snake's limited production run was canned because the car cost too much - it was twice the price of a regular GT500 - and thus just this one exists. It's been lightly restored over the years, and more recently shod in a set of the now-rare Thunderbolt tyres, and will go under the hammer in May at Mecum Auctions' Original Spring Classic sale. No word on price, but it will be quite a big one...

Have a click through the pics and tell us just how cool this original Shelby Super Snake really is (clue: very). Go on, do it for Carroll.